A method of producing a multi-layer ceramic electronic component includes: preparing a multi-layer unit including ceramic layers laminated in a direction of a first axis, internal electrodes disposed between the ceramic layers, and first and second side surfaces facing each other in a direction of a second axis orthogonal to the first axis, the internal electrodes being exposed from the first and second side surfaces; thermocompression-bonding a first side margin sheet to the first side surface; forming a first side margin by punching the thermocompression-bonded first side margin sheet with the first side surface; thermocompression-bonding a second side margin sheet to the second side surface, the second side margin sheet including a bonding surface having a higher flexibility than the first side margin formed on the first side surface; and forming a second side margin by punching the thermocompression-bonded second side margin sheet with the second side surface.