The present invention may lower the cost, save space and simplify assembly in a medium conveyance mechanism that conveys a medium with a pair of conveyance rollers provided facing each other. Namely, the medium conveyance mechanism is disposed with a torsion spring including a coil portion and arms at both ends of the coil portion; a first fixing wall that fixes one arm of the torsion spring; and a second fixing wall that fixes the coil portion at an opposite side from the first fixing wall, wherein the other arm of the torsion spring is made to contact a following roller shaft at the first fixing wall side.