To provide a front fork applicable to both erecting and inverting types, wherein a weight of an outer tube is not increased even if a rigidity in a fore-and-aft direction of the front fork is increased so as to be downsized, and both material saving and cost reduction are achieved.

In the front fork where the outer tube 2 is slidably inserted in the outer circumference of an inner tube 1 through a bearing 3, the outer and inner tubes are constituted into a cylinder shape. Inner circumferential walls of both sides of the outer tube are cut off along an axial direction to form thin walls, and an oil sump 11 is formed between the inner circumferences 8 of both the sides and the outer circumference of the inner tube.