Disclosed herein is an automatic transmission (1) including first and second planetary gear sets (PL1) and (PL2). The first planetary gear set (PL1) has a first sun gear (S1) to which power from a power source (4) is input via an input shaft (3), and a first ring gear (R1) engaged with a first brake (B1). The second planetary gear set (PL2) has a second ring gear (R2) always engaged with a first carrier (C1), a second sun gear (S2) engaged with a second brake (B2), and a second carrier (C2) engaged with an output (output gear (7)). The automatic transmission is configured to engage the first and second brakes in a first gear to allow the power from the power source to be transmitted to the output via the input shaft and the first and second planetary gear sets.