PURPOSE: To provide an axle type suspension device having a simple structure with a small number of parts as well as light weight, allowing an easy repair work and reducing a noise during a travel.

CONSTITUTION: A trunnion shaft 43 is laid so as to pass through trunnion brackets 42 fixed to both side rails 41 of a frame, and further passed rotatably through a trunnion sheet 44 attached to each trunnion bracket 42. Also, leaf springs 45 and 46 with eye sections 49 and 50 formed at both ends are fastened to the upper and lower sides of each sheet 44, and the sections 49 and 50 of the springs 45 and 46 are held on spring brackets 54 and 55 laid in a rear axle housing. Then, spring pins 52 and 52 are inserted through the brackets 54 and 55 for supporting each of the springs 45 and 46.