The present invention relates to a pendulum-type gate valve installed to control a flow of fluid between a process chamber and a vacuum pump in a vacuum equipment configuration of a display manufacturing process or a semiconductor manufacturing process. The gate valve has a simple structure since a rotating body is utilized as a housing of a cylinder and upper and lower seal plates are used as a driving shaft. The upper and lower seal plates operate in T-motion based on the rotating body, to increase stability of operation, and make a count-pressure response possible and minimize a friction driving part. As there is one air cylinder space in the rotating body, only one air supply passage is provided. The order of the T-motion operation is determined by using a spring and read by a beam sensor to prevent malfunction of the valve and alleviate the impact of the valve operation. During equipment repair, the friction driving part can be repaired while the rotating body is pulled out of the valve but not separated from the process chamber and the vacuum pump. The gate valve also has a structure in which only rotational motion is made without linear motion of the rotating body and a rotating shaft is supported with upper and lower bearings, which can minimize the sag of the seal plates.