An automatic transmission device (10, 11, 12, 13, 14, 15) for a vehicle includes a first planetary gear mechanism (P1), a second planetary gear mechanism (P2), a third planetary gear mechanism (P3), a fourth planetary gear mechanism (P4), an input shaft (N), an output shaft (T), six engaging elements including a first engaging element (M1), a second engaging element (M2), a first clutch (CL1), a second clutch (CL2), a third clutch (CL3) and a brake (B1), a first connection member (J1), a second connection member (J2), a third connection member (J3), a fourth connection member (J4), a fifth connection member (J5), a sixth connection member (J6), a seventh connection member (J7), an eighth connection member (J8), and a ninth connection member (J9). According to the invention, transmission efficiency and flexibility of a transmission device can be improved.