Provided is a tablet cassette in which a means for inhibiting a rotor from rotating when the tablet cassette is not mounted is simplified so as to suppress cost increase. A plurality of to-be-engaged parts 61 are provided continuously in the circumferential direction with predetermined intervals therebetween in an annular inner surface region of a bottom wall, the bottom wall being centered on the axis of a hollow rotation shaft 23 and being spaced apart by a predetermined distance from the rotation shaft. A sliding shaft 70 is also provided, the sliding shaft rotating together with the rotation shaft 23, and being disposed to be slidable in the axial direction inside the rotation shaft 23 so as to displace to a rotor body 22A side when the rotation shaft 23 is connected to a drive shaft 33 and so as to displace to a bottom wall 21B side when the rotation shaft 23 is not connected to the drive shaft 33. At least two engaging parts 71, which engage with some of the plurality of to-be-engaged parts 61, are provided to an arm 72 that is provided to the sliding shaft 70.
