A posture holding device is for use in a transfer device which has a holding part configured to hold an object and a first link and a second link connected to the holding part. The transfer device moves the first link and the second link relative to the holding part so as to move the holding part between a transfer position and a standby position. The posture holding device holds a posture of the holding part and includes a magnetic gear rotatably connecting the first link and the second link to the holding part. The magnetic gear is disposed such that the one end of the first link connected to the holding part is rotated about a first axis and the one end of the second link connected to the holding part is rotated about the first axis or a second axis different from the first axis.