The pilot stated that the intent of the flight was to conduct touch-and-go landings in the twin-engine, retractable-gear airplane. He stated that he made a "textbook" first landing, and that during the landing rollout, he attempted to raise the wing flaps for takeoff. The pilot "mistook the gear lever for the flaps" and the landing gear began to retract. He added power to "overcome the sinking," but the right propeller struck the ground, and the airplane "spun to the right." The airplane came to rest upright, in a grassy area between the runway and taxiway. The airplane sustained substantial damage to the wings, fuselage, and empennage. The pilot reported 50 hours of flight time in the accident airplane, and flew it "every couple of weeks." The pilot's most recent experience in the accident airplane make and model was 30 days prior to the accident. The airplane's landing gear and flap control levers were the same color and approximately the same size, but were located on opposite sides of the control column.