To improve working efficiency when a unitized object obtained by winding a timing chain around a crank sprocket and the like, and incorporating a timing chain guide device to them is inserted into a timing-chain storage space that is cast-formed on a cylinder block or the like.

The device includes: a first timing chain guide 2 and a second timing chain guide 3 for guiding the timing chain 7; an erected part 4 which is built between the first and second timing chain guides 2 and 3; and a first leg 51 and a second leg 52 each extended from the erected part 4 toward bosses 742 on both sides of a sprocket tooth 741 of the crank sprocket 74. A gap amount S2 between a tip of the second leg 52 and one of the bosses 742 is larger than a gap amount S1 between a tip of the first leg 51 and the other of the bosses 742.