To provide an inexpensive image pickup lens ensuring mass productivity and preventing deterioration of images due to fluctuation of a paraxial image-point position caused by water absorption, image pickup device, digital apparatus, and a manufacturing method of the image pickup lens, the image pickup lens includes: at least one lens block including a lens substrate, and a lens portion or lens portions formed on at least one of an object-side surface or an image-side surface of the lens substrate. The lens portion is formed of an energy-curable resin material which is different from a material of the lens substrate. At least one lens portion has a dimension change rate caused by water absorption which is larger than a dimension change rate caused by water absorption of the lens substrate, and satisfies the predetermined expression about a change in refractive index the energy-curable resin material caused by water absorption.