To provide a power transmission device capable of precluding any obstruction to the steering likely caused by such an occurrence that splinters of a resilient member intrude into a rack housing, without using a costly material.

The power transmission device is structured so that a rack shaft 2 is incorporated in the rack housing 1, a pinion 13 is meshed with a rack 2a formed on the rack shaft, and that the shaft of a power transmitting system is coupled with the end of the rack shaft through a coupling means 4, wherein a cushion accommodation part is provided in either of the open end part of the rack housing and the coupling means, and inside the cushion accommodation part the resilient member 9 is incorporated and also a sliding member 10 on its outside, and at the stroke end of the rack shaft, the coupling means or the rack housing collides with the sliding member, and the resilient member is compressed while the sliding member is sliding.