To improve reliability and assemblability of a semiconductor device.

In a die bonding process, a semiconductor chip 1 is picked up using an electrostatic suction collet 9 having a flat sucking surface 9a and an inner electrode for generating a suction force and having a relation in which the size of the sucking surface 9a is not lower than the size of a main surface 1a of the semiconductor chip 1. Thus, the semiconductor chip 1 can be sucked and held while pressing the entire surface to be sucked, and the external periphery of the semiconductor chip 1 can be prevented from warpage when being peeled off from a dicing tape 12. In this way, damages of the semiconductor chip 1 such as cracks or chipping of the semiconductor chip 1 in picking up can be prevented from occurring, and the reliability of the semiconductor device can be improved.