PURPOSE: To pump a particulate solid substance without effective heating of the substance by constituting a rotary flow channel having an inlet and an outlet by an annular drug flow channel segment and a linear channel segment.

CONSTITUTION: A solid substance pump 1 has a mechanical compressor 13, and forces a feeding substance into a flow channel 12 via an opening 137 in a chamber 130 at a lower end of a hopper 139. The channel 12 is limited by a first annular drug flow part L1 formed between a stator 14 and a rotor 16, and a wedge-shaped deflecting plate 18 is brought into slide contact with a wall of the rotor 16 for limiting a rotary part of the channel 122 by its to end 181. A linear channel segment L2 is formed between a wall part 148 of a first plane of the stator 14 and a wall 182 of a second plane for supplying the plate 18.