To provide a shaft device with a bearing capable of easily assembling a block body and reducing the costs without generating a press-in flaw on the a block body such as a cam block on the outer diameter surface of a shaft.

The block body 14 and the rolling bearing 31 are disposed at a predetermined interval in an axial direction of the outside diameter surface of the shaft 12. A middle connection member 40 is assembled to a shaft portion in which the block body 14 of the outside diameter surface of the shaft 12 is disposed. The block body 14 is fitted and secured to the outside diameter surface of the shaft 12 via the middle connection member 40.