An image reading device includes a scanner casing fixed to an upper side of a body frame of an image forming apparatus body, a document pressing member that covers an upper surface of the scanner casing, a leg part provided to be movable with respect to the scanner casing in a vertical direction, a stationary part fixed to an upper end of the leg part, a rotating part connected rotatably to the stationary part via a hinge shaft and supporting the document pressing member, a holding mechanism to hold an opening angle of the document pressing member, and cylindrical parts, passing through the scanner casing in the vertical direction, and having lower end portions fixed to the body frame. The leg part is inserted into the cylindrical part from an upper end opening of the cylindrical part and inclined to a side of the document pressing member.