An automatic transmission is provided with three planetary gear units and five friction elements that establish at least six forward speeds and one reverse speed by engaging different combinations of three out of five friction elements simultaneously. In the automatic transmission, an output shaft is always connected to a first ring gear of the first planetary gear unit. A second ring gear of the second planetary gear unit is always fixed. A first carrier of the first planetary gear unit and a third ring gear of the third planetary gear unit are connected together to form a first rotating member. A second sun gear of the second planetary gear unit and a third carrier of the third planetary gear unit are connected together to form a second rotating member.