A compact excavator includes an operator's cab with a door capable of opening and closing an opening surface forming a boarding port. The door includes one door piece, and has a flexing portion which is closer to a front pillar than the central portion of the door when the door is in a closed state. The flexing portion is shaped to have a first area so formed that when the door is in a closed state, the first area approaches the opening surface as the first area approaches the front pillar, and a second area arranged continuously with the first area and nearer the front pillar than the first area and being formed so that the second area draws away from the opening surface as the second area approaches the front pillar.