13 and a thin assistant fabric 14 which supports the ventilation fabric the ventilation fabric 13 is made from a knit fabric in which three holes 15 a 15 b and 15 c with different sizes and shapes are arranged in a certain construction the holes of the ventilation fabric 13 may have at least two sizes and shapes at certain portions and one hole can be formed at a portion where the user wants to enhance customized ventilation effects the thin assistant fabric 14 supports the ventilation fabric 13 the construction of the fabric of the left side customizable ventilation panel 12 is the same as the right side customizable ventilation panel 11 the holes of the right and left side customizable ventilation panels 11 and have different sizes and shapes at one panel when manufacturing the cap larger size holes may be provided at a portion where the user wants to enhance customized ventilation effects so the present invention can provide customizable ventilation functions exclusively working for each separate portions where the user wants to form the holes in addition the right and left side customizable ventilation panels 11 and 12 can be applied to the brim part except for the crown part the holes with different sizes and shapes can be formed at each of the right and left side customizable ventilation panels 11 and 12 so the cap of the present invention can provide aesthetic effects fig3 is a perspective view illustrating a cap according to another embodiment of the present invention and fig4 is an enlarged cross sectional view taken along line b b u2032 of fig3 as shown in.