A bus bar module includes an output terminal that has a male screw, a tab for preventing a wiring terminal from being rotated subserviently, and a terminal connecting portion with which a terminal of a battery element in a battery pack is connected, and a module main body from which a portion of a terminal installation portion to which the output terminal is installed is protruded. The terminal installation portion has an engagement tab that elastically deforms during an installation of the output terminal and recovers after the installation to engage the output terminal with the terminal installation portion. The tab is located so as to prevent a tool from contacting with the engagement tab when connecting the terminal connecting portion with the terminal of the battery element. According to the module, the output terminal can be prevented from dropping off even during its installation to the battery pack.