To provide a film forming method capable of obtaining a high-quality perovskite type oxide thin film, piezoelectric element having a piezoelectric substance constituted of the thin film formed by the film forming method, liquid discharge head having the piezoelectric element and liquid discharge apparatus having the liquid discharge head. A method for forming a perovskite type oxide thin film having a composition expressed by (A1x, A2y A3z) (B1j, B2k, B3l, B4m B5n)Op is included, which is a film forming method having a plurality of steps for supplying a material containing the elements onto the substrate, dividing the elements A1 to A3 and B1 to B5 into a plurality of groups and supplying each material containing the elements included in the groups onto the substrate in separate steps.