A valve timing controller comprising: a driving-side rolling body configured to rotate synchronously with a crankshaft of an internal combustion engine; a driven-side rolling body which is coaxially held in the driving-side rolling body through a sealing member and is configured to rotate in a unified manner with a camshaft for opening/closing a valve of the internal combustion engine, relative to the driving-side rolling body; an advance chamber configured to move a relative rotation phase of the driven-side rolling body relative to the driving-side rolling body in an advance direction by a volume increase of the advance chamber through an operating oil supply, and a retard chamber configured to move the relative rotation phase in a retard direction by a volume increase of the retard chamber through an operating oil supply, the advance chamber and the retard chamber being formed of the driving-side rolling body and the driven-side rolling body; a torsion spring which is disposed in a space formed between a front plate or a rear plate of the driving-side rolling body and the driven-side rolling body and is configured to bias at all times the driving-side rolling body and the driven-side rolling body in the advance direction or the retard direction; and a first cylindrical portion provided in the front plate or the rear plate and a second cylindrical portion provided in the driven-side rolling body, the first and second cylindrical portions (1a, 2a) being insertable into each other in an axial direction, wherein a recess is provided in one side face of the driven-side rolling body, into which recess an end portion of the camshaft is insertable, characterized in that the second cylindrical portion is representing an inner diameter-side wall of an annular groove formed in an end face on an opposite side to a side of the camshaft from among end faces of the driven-side rolling body, an opening diameter of the recess is made larger than an inner diameter of a hole formed in the rear plate into which the camshaft is insertable, and a difference between the opening diameter of the recess and the inner diameter of the hole is set larger than a gap size in the radial direction between the first cylindrical portion and the second cylindrical portion. a driving-side rolling body configured to rotate synchronously with a crankshaft of an internal combustion engine; a driven-side rolling body which is coaxially held in the driving-side rolling body through a sealing member and is configured to rotate in a unified manner with a camshaft for opening/closing a valve of the internal combustion engine, relative to the driving-side rolling body; an advance chamber configured to move a relative rotation phase of the driven-side rolling body relative to the driving-side rolling body in an advance direction by a volume increase of the advance chamber through an operating oil supply, and a retard chamber configured to move the relative rotation phase in a retard direction by a volume increase of the retard chamber through an operating oil supply, the advance chamber and the retard chamber being formed of the driving-side rolling body and the driven-side rolling body; a torsion spring which is disposed in a space formed between a front plate or a rear plate of the driving-side rolling body and the driven-side rolling body and is configured to bias at all times the driving-side rolling body and the driven-side rolling body in the advance direction or the retard direction; and a first cylindrical portion provided in the front plate or the rear plate and a second cylindrical portion provided in the driven-side rolling body, the first and second cylindrical portions (1a, 2a) being insertable into each other in an axial direction, wherein a recess is provided in one side face of the driven-side rolling body, into which recess an end portion of the camshaft is insertable, characterized in that the second cylindrical portion is representing an inner diameter-side wall of an annular groove formed in an end face on an opposite side to a side of the camshaft from among end faces of the driven-side rolling body, an opening diameter of the recess is made larger than an inner diameter of a hole formed in the rear plate into which the camshaft is insertable, and a difference between the opening diameter of the recess and the inner diameter of the hole is set larger than a gap size in the radial direction between the first cylindrical portion and the second cylindrical portion.