A body of an oil level gauge includes an upper end, a lower end, a surface, a measurement portion, and a projecting portion. The projecting portion includes a middle portion and a lower portion. The middle portion is located at a center in the width direction of the body in the projecting portion. A first slope surface is inclined from the middle portion in the lower portion to a first end in the width direction in the lower portion. A second slope surface is inclined from the middle portion in the lower portion to a second end in the width direction in the lower portion. The middle portion is a part of the projecting portion located at a farthest position from the surface in a direction vertical to the surface. The middle portion is located closer to the upper end than the first end and the second end.