In a strut type shock absorber (1), a lower cap (2) is welded onto an inner circumferential surface of an outer shell (3) at a step (16) formed in a retreated position from an axial tip of the outer shell (3). The axial tip of the outer shell (3) is welded onto the inner circumferential surface of a knuckle bracket (6) which holds the outer shell (3). Since welding of the lower cap (2) onto the outer shell (3) and welding of the knuckle bracket (6) onto the outer shell (3) are conducted at different positions, the lower cap (2) is welded onto the outer shell (3) without suffering from blowholes irrespective of the material forming the knuckle bracket (6), and as a result, a weld bead (17) having a high degree of air-tightness is formed.