A roller bearing includes an inner ring, an outer ring, a plurality of cylindrical
rollers each provided between rolling contact surfaces of the inner ring and the
outer ring. Each of the cylindrical rollers includes an end face having a peripheral
part that is crowned. A flange portion is formed at an outer circumferential face
end part of the inner ring and/or an inner circumferential face end part of the
outer ring. The peripheral part is crowned in a curving shape represented by an
exponential function of y=aexp(-bx); where a and b are constants, x
is a distance from the rolling contact surface in a radial direction of the cylindrical
roller, and y is a crowning fall-off amount from a central part of the end face
of the cylindrical roller in an axial direction of the cylindrical roller.