A dual clutch transmission having two input shafts respectively connected to clutches, and an intermediate shaft, preventing the intermediate shaft from rotating idle when the vehicle is traveling at high speeds and avoiding excess stirring of lubricating oil in the transmission and increase in noise. In the dual clutch transmission, a direct connection clutch C3 is provided between one input shaft S2 and an output shaft S4, and an intermediate shaft connection clutch C4 for interrupting the transmission of power is provided between the intermediate shaft S3 and the output shaft S4. When the power is directly transmitted from the input shaft S2 to the output shaft S4 via the direct connection clutch C3, the intermediate shaft connection clutch C4 is disconnected to stop the rotation of the intermediate shaft S3 and to prevent the lubricating oil from being excessively stirred by the idle rotation of the intermediate shaft S3. Further, the intermediate shaft connection clutch C4 is disconnected, and a transmission step is constituted by utilizing the gear trains among the two input shafts and the intermediate shaft S3, making it possible to omit one gear train and, therefore, to shorten the length of the transmission.