A counterweight (8) is attached to the rear side of a revolving frame (6), and an engine (9) is mounted in a transverse direction in front of the counterweight (8). A heat exchanger (12) is located on the left side of the engine (9), and a left-hand side door (17) is located on the left side of the heat exchanger (12). An air cleaner (24) is accommodated in an air cleaner chamber (19) which is provided in a space enclosed by the counterweight, left-hand side door and heat exchanger. In this state, a casing (25) of the air cleaner has an opening portion (25A) to permit insertion and extraction of a filter element (26). Thus, at the time of a maintenance work for the air cleaner, one can draw out the filter element from the opening portion of the casing simply by opening the left-hand side door.