PURPOSE: To automatically connect a starting device for engine test to an engine.

CONSTITUTION: A cell motor 13 is provided on a supporting member 16 fitted on a starting shaft 5 rotated freely relative to the shaft 5. The cell motor 13 is connected to the starting shaft 5 through a drive gear 12 and a driven gear 11. Then a cylinder device 27 for rotating the supporting member 16 is provided. The cell motor 13 is rotated relatively with the supporting member 16 around the starting shaft 5 by the driving of the cylinder device 27 to rotate the shaft 5 at low speed through the drive gear 12 and the driven gear 11. Accordingly, the starting shaft 5 is moved to an engine 2 side by the driving of the cylinder device 27 to connect it to the main shaft 4 automatically. Thus an engine can be tested efficiently to save labor and reduce cost, and personal accident by manual operation can be prevented.