Powertrain device for vehicle

A powertrain device for a vehicle, comprising:

• an engine;
• an automatic transmission;
• and
• a motive power connection-disconnection clutch arranged between the engine and the automatic transmission, wherein
• the automatic transmission includes a plurality of friction fastening elements for selectively switching motive power transmitting paths,
• a predetermined friction fastening element among the plurality of friction fastening elements is a travel-start friction fastening element performing slip control in which the travel-start friction fastening element is completely fastened through a slip state in a travel start of the vehicle, and
• the motive power connection-disconnection clutch is released at least in an engine start and is fastened earlier than the travel-start friction fastening element in the travel start.