the grooves the clothing c is steamed and hence the steam can be effectively applied to the clothing c on the other hand some components of the steam s generated by the steam iron 200 are appropriately released inside the base material 2 through steam holes 8 excessive steam s components are released to air through steam holes 8 formed in the back surface of the base material 2 furthermore since the longitudinal and lateral grooves 18 and 19 and the projections 20 serve as heat radiation members heat generated from the iron can be appropriately radiated therefore the base material 2 can be formed of a blow molded material having a low heat resistant temperature note that in the above embodiment the longitudinal and lateral grooves are formed in the base material 2 however grooves may be formed obliquely in a diamond shape or recesses may be locally formed with this structure the same result can be obtained as a matter of course referring to fig1 a in order to obtain a ship like shape shown in the drawing a head 12 and a border 15 are formed referring to fig1 c in this embodiment a border 15 and a linear side are formed referring to fig1 c in this embodiment two linear sides are formed when the pressing board 1 is constructed.