A construction machine comprising: an engine; a variable displacement first hydraulic pump (12 - 15) driven by the engine; a first hydraulic actuator (1, 3, 7) driven by pressure liquid delivered from the first hydraulic pump (12 - 15); an operation device configured to give instructions for an operation direction and a demanded velocity of the first hydraulic actuator (1, 3, 7); a controller configured to control a delivery flow rate of the first hydraulic pump (12 - 15) according to an input from the operation device; and a pressure sensor (60a, 60b, 61a, 61b, 62a, 62b); wherein the controller includes: a demanded torque estimating section configured to estimate demanded torque as torque demanded from the engine by the first hydraulic pump (12 - 15) based on the demanded velocity of the first hydraulic actuator (1, 3, 7); and a command calculating section configured to calculate the delivery flow rate of the first hydraulic pump (12 - 15); characterized in that the pressure sensor (60a, 60b, 61a, 61b, 62a, 62b) is configured to detect a load pressure on the first hydraulic actuator (1, 3, 7), the demanded torque estimating section is configured to estimate the demanded torque based on the demanded velocity of the first hydraulic actuator and on the load pressure on the first hydraulic actuator (1, 3, 7), the controller further includes a demanded velocity limiting section configured to, in a case in which a demanded torque change rate as a change rate of the demanded torque exceeds a predetermined change rate, limit the demanded velocity such that the demanded torque change rate becomes equal to or lower than the predetermined change rate, and the command calculating section is configured to calculate the delivery flow rate of the first hydraulic pump (12 - 15) based on the demanded velocity of the first hydraulic actuator (1, 3, 7), the demanded velocity being limited by the demanded velocity limiting section. an engine; a variable displacement first hydraulic pump (12 - 15) driven by the engine; a first hydraulic actuator (1, 3, 7) driven by pressure liquid delivered from the first hydraulic pump (12 - 15); an operation device configured to give instructions for an operation direction and a demanded velocity of the first hydraulic actuator (1, 3, 7); a controller configured to control a delivery flow rate of the first hydraulic pump (12 - 15) according to an input from the operation device; and a pressure sensor (60a, 60b, 61a, 61b, 62a, 62b); wherein the controller includes: a demanded torque estimating section configured to estimate demanded torque as torque demanded from the engine by the first hydraulic pump (12 - 15) based on the demanded velocity of the first hydraulic actuator (1, 3, 7); and a command calculating section configured to calculate the delivery flow rate of the first hydraulic pump (12 - 15); characterized in that the pressure sensor (60a, 60b, 61a, 61b, 62a, 62b) is configured to detect a load pressure on the first hydraulic actuator (1, 3, 7), the demanded torque estimating section is configured to estimate the demanded torque based on the demanded velocity of the first hydraulic actuator and on the load pressure on the first hydraulic actuator (1, 3, 7), the controller further includes a demanded velocity limiting section configured to, in a case in which a demanded torque change rate as a change rate of the demanded torque exceeds a predetermined change rate, limit the demanded velocity such that the demanded torque change rate becomes equal to or lower than the predetermined change rate, and the command calculating section is configured to calculate the delivery flow rate of the first hydraulic pump (12 - 15) based on the demanded velocity of the first hydraulic actuator (1, 3, 7), the demanded velocity being limited by the demanded velocity limiting section. a demanded torque estimating section configured to estimate demanded torque as torque demanded from the engine by the first hydraulic pump (12 - 15) based on the demanded velocity of the first hydraulic actuator (1, 3, 7); and a command calculating section configured to calculate the delivery flow rate of the first hydraulic pump (12 - 15); characterized in that the pressure sensor (60a, 60b, 61a, 61b, 62a, 62b) is configured to detect a load pressure on the first hydraulic actuator (1, 3, 7), the demanded torque estimating section is configured to estimate the demanded torque based on the demanded velocity of the first hydraulic actuator and on the load pressure on the first hydraulic actuator (1, 3, 7), the controller further includes a demanded velocity limiting section configured to, in a case in which a demanded torque change rate as a change rate of the demanded torque exceeds a predetermined change rate, limit the demanded velocity such that the demanded torque change rate becomes equal to or lower than the predetermined change rate, and the command calculating section is configured to calculate the delivery flow rate of the first hydraulic pump (12 - 15) based on the demanded velocity of the first hydraulic actuator (1, 3, 7), the demanded velocity being limited by the demanded velocity limiting section.