PURPOSE: To reduce the number of parts and simplify the installation work in the mounting structure of a guide device used in a roller conveyer for pallet transportation, by forming a dovetail groove, whose outside is open, at the lower edge of the rail material of a guide device, and pressing a holding member against the held part of a side frame and the inner and outer surfaces of the rail material for bolt-tightening.

CONSTITUTION: A side frame 1A is formed by means of aluminum extrusion, and a held part 21 consisting of recessed grooves 20A, 20B are integratedly formed at the upper part in a longitudinal direction. Moreover, a guide device 22 is constituted out of an aluminum extruded part, a rail material 23 provided with a dovetail groove 25 in a longitudinal direction whose outside is open and a guide plate 24. The guide device 22 is installed on the side plate 1A by pressing holding members 31, 32 against the held part 21 of the side plate 1A and the outside and inside of the rail material 23 respectively to fix them with a nut body 40 in the dovetail groove part 25 and a bolt 41, and a bolt 37 and a screw 36 of the holding member 32. It is thus possible to reduce the number of parts, and facilitate installation.