In order to retrieve a specific block from a machining program, a numerical controller calculates the distance between a command path based on one of blocks included in the machining program and a current position of a tool and, based on the calculated distance, displays only that one of the blocks included in the machining program which is located closest to the current tool position or displays a plurality of blocks side by side in the ascending order of distance from the current tool position.

In order to retrieve a specific block from a machining program, a numerical controller calculates the distance between a command path based on one of blocks included in the machining program and a current position of a tool and, based on the calculated distance, displays only that one of the blocks included in the machining program which is located closest to the current tool position or displays a plurality of blocks side by side in the ascending order of distance from the current tool position.