A construction machine provided with an attachment (15, 50) having a leading end attachment (6, 54), the construction machine comprising: an attachment state detecting device (12, 55) which is configured to detect a state of the attachment (15, 50); a display device; and a controller, wherein the controller includes: an attachment positional information generation section which is configured to generate attachment positional information concerning a position of the attachment (15, 50) based on the state of the attachment (15, 50) detected by the attachment state detecting device (12, 55); and a display control section which is configured to control the display device to display attachment relevant information generated based on the attachment positional information generated by the attachment positional information generation section and three-dimensional contour information concerning a three-dimensional contour of a peripheral working area around the construction machine, wherein the attachment relevant information is information concerning an image obtained by superimposing a peripheral image about the three-dimensional contour of the peripheral working area and a projected image about the leading end attachment (6, 54) which is projected to the peripheral image in a projection direction, characterized in that the controller is configured to generate projection directional information for setting the projection direction based on input information concerning the projection direction input by an operator. an attachment state detecting device (12, 55) which is configured to detect a state of the attachment (15, 50); a display device; and a controller, wherein the controller includes: an attachment positional information generation section which is configured to generate attachment positional information concerning a position of the attachment (15, 50) based on the state of the attachment (15, 50) detected by the attachment state detecting device (12, 55); and a display control section which is configured to control the display device to display attachment relevant information generated based on the attachment positional information generated by the attachment positional information generation section and three-dimensional contour information concerning a three-dimensional contour of a peripheral working area around the construction machine, wherein the attachment relevant information is information concerning an image obtained by superimposing a peripheral image about the three-dimensional contour of the peripheral working area and a projected image about the leading end attachment (6, 54) which is projected to the peripheral image in a projection direction, characterized in that the controller is configured to generate projection directional information for setting the projection direction based on input information concerning the projection direction input by an operator. an attachment positional information generation section which is configured to generate attachment positional information concerning a position of the attachment (15, 50) based on the state of the attachment (15, 50) detected by the attachment state detecting device (12, 55); and a display control section which is configured to control the display device to display attachment relevant information generated based on the attachment positional information generated by the attachment positional information generation section and three-dimensional contour information concerning a three-dimensional contour of a peripheral working area around the construction machine, wherein the attachment relevant information is information concerning an image obtained by superimposing a peripheral image about the three-dimensional contour of the peripheral working area and a projected image about the leading end attachment (6, 54) which is projected to the peripheral image in a projection direction, characterized in that the controller is configured to generate projection directional information for setting the projection direction based on input information concerning the projection direction input by an operator.