An automatic transmission including three single pinion planetary gearsets and six friction elements, in which an input shaft is always connected to a first sun gear of a first planetary gearset, the output shaft is always connected to a second ring gear of a second planetary gearset, a third sun gear of a third planetary gearset is always kept in a fixed state relative to a transmission case of the automatic transmission, a first ring gear of the first planetary gearset and a third pinion carrier of the third planetary gearset are always connected to each other and constitute a first rotary member, and at least eight forward speeds and one reverse speed are respectively established by simultaneous engagements of three friction elements selected from the six friction elements.