The washing nozzle for washing an inside of the machine tool with fluid includes a base portion having a tubular passage inside thereof, a supply port through the tubular passage, and a rotary member rotatable about an axis parallel to a surface on which the base portion is mounted, the rotary member having inside thereof a nozzle jet port and a nozzle flow passage allowing communication between the tubular passage and the nozzle jet port, wherein the jet port is formed so that fluid jetted from the jet port of the rotary member hits the surface on which the base portion is mounted and the jet of the fluid causes the rotary member to rotate about the parallel axis.