PURPOSE: To closely form bumps which can be favorably maintained with high productivity by exposing, developing, and curing photosensitive conductive past composed of fine particles of a metal, carbon, and other conductive substances and photosensitive polyimide after applying and drying the paste to and on a wafer.

CONSTITUTION: Photosensitive paste 16 prepared by mixing fine Ag particles with photosensitive polyimide and kneading the mixture is applied to a silicon wafer 1 in a uniform thickness by dispensing the paste on the wafer 1 and rotating the wafer 1. Then the wafer 1 is placed on a hot plate 17 and the paste 16 is dried. After cooling the paste 16, the paste 16 is exposed, developed, and rinsed. Thereafter, the paste 16 is cured and bumps 19 are formed. Therefore, the bumps which can be favorably maintained can be closely formed with high productivity by using a less number of facilities.