An electric connection box is mounted within an engine room of a vehicle. A bus bar and a current sensor are sequentially mounted on a lower cover, and an upper cover is joined to the lower cover to cover the bus bar and the current sensor. The current sensor is molded integrally with the upper cover. With this construction, the current sensor and the bus bar are less liable to be displaced relative to each other, and the number of the component parts, as well as time and labor required for an assembling operation, is reduced.