A radio communication device comprising: a first substrate (11, 111) whose base material is a dielectric material and on which a radio communication circuit (12, 112) is provided, the radio communication circuit (12, 112) being a circuit for making a conversion between (i) a high frequency signal in a millimeter wave band and (ii) a baseband signal having a frequency lower than that of the high frequency signal; a second substrate on which a baseband circuit for processing the baseband signal is provided, and an antenna which includes a waveguide and a reflector, at least a halfway part of the first substrate (11, 111) being flexible, the first substrate (11, 111) including: a terminal (14, 114) which is provided in a vicinity of an edge (11a, 111a) of the first substrate (11, 111) and to which the baseband signal is supplied from the second substrate; a transmission line (13, 15, 113, 115) through which the baseband signal is transmitted from the terminal (14, 114) to the radio communication circuit (12, 112), and a probe through which the high frequency signal is fed to the antenna; the second substrate including a card-edge connector which is electrically connected to the baseband circuit and which supplies the baseband signal to the terminal (14, 114); wherein one of end parts of the waveguide being electromagnetically coupled to a leading end of the probe, and the other of the end parts of the waveguide being electromagnetically coupled to the reflector; characterized in that the radio communication device further comprises: a housing in which the first substrate (11, 111), the second substrate, and the one of the end parts of the waveguide are housed; and a first metal member and a second metal member (42, 42A) sandwiching a region of the first substrate (11, 111) in which region the radio communication circuit (12, 112) and the probe are provided, a through-hole being formed in a location of the first metal member which location corresponds to the leading end of the probe, through the through-hole the leading end of the probe being electromagnetically coupled to the one of the end parts of the waveguide, at least one of the first metal member and the second metal member (42, 42A) being fixed to the housing so as to hold the first substrate (11, 111). a first substrate (11, 111) whose base material is a dielectric material and on which a radio communication circuit (12, 112) is provided, the radio communication circuit (12, 112) being a circuit for making a conversion between (i) a high frequency signal in a millimeter wave band and (ii) a baseband signal having a frequency lower than that of the high frequency signal; a second substrate on which a baseband circuit for processing the baseband signal is provided, and an antenna which includes a waveguide and a reflector, at least a halfway part of the first substrate (11, 111) being flexible, the first substrate (11, 111) including: a terminal (14, 114) which is provided in a vicinity of an edge (11a, 111a) of the first substrate (11, 111) and to which the baseband signal is supplied from the second substrate; a transmission line (13, 15, 113, 115) through which the baseband signal is transmitted from the terminal (14, 114) to the radio communication circuit (12, 112), and a probe through which the high frequency signal is fed to the antenna; a terminal (14, 114) which is provided in a vicinity of an edge (11a, 111a) of the first substrate (11, 111) and to which the baseband signal is supplied from the second substrate; a transmission line (13, 15, 113, 115) through which the baseband signal is transmitted from the terminal (14, 114) to the radio communication circuit (12, 112), and a probe through which the high frequency signal is fed to the antenna; the second substrate including a card-edge connector which is electrically connected to the baseband circuit and which supplies the baseband signal to the terminal (14, 114); wherein one of end parts of the waveguide being electromagnetically coupled to a leading end of the probe, and the other of the end parts of the waveguide being electromagnetically coupled to the reflector; characterized in that the radio communication device further comprises: a housing in which the first substrate (11, 111), the second substrate, and the one of the end parts of the waveguide are housed; and a first metal member and a second metal member (42, 42A) sandwiching a region of the first substrate (11, 111) in which region the radio communication circuit (12, 112) and the probe are provided, a through-hole being formed in a location of the first metal member which location corresponds to the leading end of the probe, through the through-hole the leading end of the probe being electromagnetically coupled to the one of the end parts of the waveguide, at least one of the first metal member and the second metal member (42, 42A) being fixed to the housing so as to hold the first substrate (11, 111). a housing in which the first substrate (11, 111), the second substrate, and the one of the end parts of the waveguide are housed; and a first metal member and a second metal member (42, 42A) sandwiching a region of the first substrate (11, 111) in which region the radio communication circuit (12, 112) and the probe are provided, a through-hole being formed in a location of the first metal member which location corresponds to the leading end of the probe, through the through-hole the leading end of the probe being electromagnetically coupled to the one of the end parts of the waveguide, at least one of the first metal member and the second metal member (42, 42A) being fixed to the housing so as to hold the first substrate (11, 111).