Abstract: A flash unit of a lens-fitted photo film unit has a positive contact member and a negative contact member for holding a battery between them. A main body portion has a couple of supporting projections formed integrally therewith. With a battery being nipped between the positive and negative contact members, the flash unit is mounted to the main body portion, so the battery is securely placed between the supporting projections. On manufacturing another lens-fitted photo film unit that contains a shorter battery than the battery, the shorter battery is connected in series to a conductive connection member, and nipped together with the connection member between the positive and negative contact members. Then the battery and the connection member are held between the supporting projections.