To intermittently perform sure lubrication to each piece of a chain by directly driving a rotary valve by a chain sprocket meshed with the chain, and making the number of communication holes of a valve element the same as the number of teeth of the sprocket.

With the number of communication holes of a valve element being set the same as the number of tooth 6a of a chain sprocket 6, communication between an inlet port and an outlet port 7a of a rotary valve 4 is made for every pitch rotation of the sprocket 2 meshing with a roller chain 1. The inlet port of the valve 4 is communicated with a lubricator 3 and applied with the pressure thereof and a lubricant pipe 5c is filled up with lubricant 3d, whereby simultaneously with the communication of the inlet port with the outlet port 7a the lubricant 3d is jetted out from a injection nozzle 2. One (1) pitch of the tooth 6a of the sprocket 6 corresponds to one piece of the roller chain 1, whereby the roller chain 1 can be surely lubricated piece by piece by the lubricant 3d jeted out from the nozzle 2.