Thermally stimulated current (TSC) and current-voltage measurements were carried out for Schottky diodes using pentacene thin films in order to investigate the relation between carrier traps and electrical conduction. Two type of TSC peaks originated from the traps at the metal-pentacene interface and in the depletion layer were observed. The current-voltage characteristics of the diodes were governed by the space charge limited conduction depending on these traps.