Mechanical properties including elastic modulus and hardness are sensitive to spacial gaps among grains in polycrystalline organic semiconducting films. Densification behavior of copper phthalocyanine films is reported under the cold (CIP) and warm (WIP) isostatic press processes. The CIP films are successfully densified at a rate of 15% and the resultant critical bending strength is improved by 1.7 times. Although the WIP films have been successfully densified at the same rate as the CIP films, the hardness and resultant bending strength of the films are still low because of the recrystallization of grains during the heating.