A horizontal articulated robot includes a first arm and a second arm respectively supported at their base end portions by a body and the tip end portion of the second arm to be rotatable about a first joint and a second joint; and a fork including its base end portion supported by the tip end portion of the second arm to be rotatable about a third joint. The first arm includes a first enlarged portion, formed in its tip end portion, with an upper surface positioned higher than an upper surface of the base end portion of the first arm. The second arm includes a second enlarged portion, formed in its tip end portion, with a lower surface positioned lower than a lower surface of the base end portion of the second arm. The first and the second enlarged portion are at least partially overlapped with each other horizontally.