A projection type image display apparatus includes an adjusting sub-frame image generator and a shift amount adjuster. The adjusting sub-frame image generator generates a primary adjusting sub-frame image having a design in which a first line having a first color and a width of an N pixel (N being a natural number) is displayed on a background image having a second color, and a secondary adjusting sub-frame image having a design in which a second line having a third color and a width of an M pixel set to N=M+α (M being an integer equal to or greater than 1, α being an integer equal to or greater than 0) is displayed on a background image having a fourth color. The shift amount adjuster adjusts the shift amount when the display positions of the primary and secondary adjusting sub-frame images on the projection surface are shifted relatively to each other.