A lead frame includes a plurality of units connected together. Each unit includes a pair of lead portions spaced apart from and opposite to each other. The lead portions are configured to mount a semiconductor element and to be electrically connected to a pair of electrodes of the semiconductor element. Each lead portion includes two hook-shaped portions respectively extending from the lead portion. The hook-shaped portions of one lead portion are arranged to surround tip portions of the hook-shaped portions of the other lead portion respectively, at both sides respective to a center line of the unit.