A rack-and-pinion type steering device includes a ball joint for connecting a rack shaft and a tie rod. The ball joint includes a socket and a ball. The socket is provided with a regulated surface allowed to contact a regulating surface of a rack housing, and a screw projecting from the regulated surface to be connected to the rack shaft. The regulated surface includes an intermediate portion having a curved surface shape that recedes from a regulating surface in a longitudinal direction of the rack shaft toward the outer circumference, and the regulated surface has such a shape that a pointed portion toward the regulating surface is less likely to be formed on the regulated surface even if a processing error occurs in the processing for forming the regulated surface of the socket.