subroutine ConstantsInit
    !
    ! constants モジュールの初期化を行います. 
    ! NAMELIST#constants_nml の読み込みはこの手続きで行われます. 
    !
    ! "constants" module is initialized. 
    ! NAMELIST#constants_nml is loaded in this procedure. 
    !
    ! モジュール引用 ; USE statements
    !
    ! NAMELIST ファイル入力に関するユーティリティ
    ! Utilities for NAMELIST file input
    !
    use namelist_util, only: namelist_filename, NmlutilMsg
    ! ファイル入出力補助
    ! File I/O support
    !
    use dc_iounit, only: FileOpen
    ! 種別型パラメタ
    ! Kind type parameter
    !
    use dc_types, only: STDOUT ! 標準出力の装置番号. Unit number of standard output
    ! メッセージ出力
    ! Message output
    !
    use dc_message, only: MessageNotify
    ! 宣言文 ; Declaration statements
    !
    implicit none
    integer:: unit_nml        ! NAMELIST ファイルオープン用装置番号. 
                              ! Unit number for NAMELIST file open
    integer:: iostat_nml      ! NAMELIST 読み込み時の IOSTAT. 
                              ! IOSTAT of NAMELIST read
    ! NAMELIST 変数群
    ! NAMELIST group name
    !
    namelist /constants_nml/ RPlanet, Omega, Grav, MolWtDry, CpDry, GasRDry, MolWtWet, CpWet, GasRWet, LatentHeat, EpsV
          !
          ! デフォルト値については初期化手続 "constants#ConstantsInit" 
          ! のソースコードを参照のこと. 
          !
          ! Refer to source codes in the initialization procedure
          ! "constants#ConstantsInit" for the default values. 
          !
    ! 実行文 ; Executable statement
    !
    if ( constants_inited ) return
    call InitCheck
    ! デフォルト値の設定
    ! Default values settings
    !
    RPlanet    = 6.371e6_DP
    Omega      = 2.0_DP * PI / ( 60.0_DP * 60.0_DP * 23.9345_DP )
    Grav       = 9.8_DP
    CpDry      = 1004.6_DP
    MolWtDry   = 28.964e-3_DP
    GasRDry    = GasRUniv / MolWtDry
    CpWet      = 1810.0_DP
    MolWtWet   = 18.01528e-3_DP
    GasRWet    = GasRUniv / MolWtWet
    LatentHeat = 2.5e6_DP 
    EpsV       = MolWtWet / MolWtDry
    ! NAMELIST からの入力
    ! Input from NAMELIST
    !
    if ( trim(namelist_filename) /= '' ) then
      call FileOpen( unit_nml, namelist_filename, mode = 'r' ) ! (in)
      rewind( unit_nml )
      read( unit_nml, nml = constants_nml, iostat = iostat_nml )   ! (out)
      close( unit_nml )
      call NmlutilMsg( iostat_nml, module_name ) ! (in)
      if ( iostat_nml == 0 ) write( STDOUT, nml = constants_nml )
    end if
    ! 印字 ; Print
    !
    call MessageNotify( 'M', module_name, '----- Initialization Messages -----' )
    call MessageNotify( 'M', module_name, '  PI         = %f', d = (/ PI         /) )
    call MessageNotify( 'M', module_name, '  GasRUniv   = %f', d = (/ GasRUniv   /) )
    call MessageNotify( 'M', module_name, '  StB        = %f', d = (/ StB        /) )
    call MessageNotify( 'M', module_name, '  FKarm      = %f', d = (/ FKarm      /) )
    
    call MessageNotify( 'M', module_name, '  RPlanet    = %f', d = (/ RPlanet    /) )
    call MessageNotify( 'M', module_name, '  Omega      = %f', d = (/ Omega      /) )
    call MessageNotify( 'M', module_name, '  Grav       = %f', d = (/ Grav       /) )
    
    call MessageNotify( 'M', module_name, '  CpDry      = %f', d = (/ CpDry      /) )
    call MessageNotify( 'M', module_name, '  MolWtDry   = %f', d = (/ MolWtDry   /) )
    call MessageNotify( 'M', module_name, '  GasRDry    = %f', d = (/ GasRDry    /) )
    
    call MessageNotify( 'M', module_name, '  CpWet      = %f', d = (/ CpWet      /) )
    call MessageNotify( 'M', module_name, '  MolWtWet   = %f', d = (/ MolWtWet   /) )
    call MessageNotify( 'M', module_name, '  GasRWet    = %f', d = (/ GasRWet    /) )
    call MessageNotify( 'M', module_name, '  LatentHeat = %f', d = (/ LatentHeat /) )
    
    call MessageNotify( 'M', module_name, '  EpsV       = %f', d = (/ EpsV       /) )
    call MessageNotify( 'M', module_name, '-- version = %c', c1 = trim(version) )
    constants_inited = .true.
  end subroutine ConstantsInit