Wafer etching apparatus

In a wafer etching apparatus for etching wafers provided with an orientation flat, composed of a casing generally shaped like a horizontally laid drum, at least two horizontal, parallel and rotative rollers having annular engagement grooves arranged at regular intervals in the axial direction to receive and support wafers vertically, and a press rod means extending in parallel with said rollers, having grooves arranged at the same intervals as said rollers to receive and guide the wafers, and maintaining the wafers in firm contact with said rollers, and a drive means to drive said rollers to rotate about their axes, an improvement comprising in that said rotative rollers are at least five in number and arranged such that the rollers cooperate to substantially circumscribe the wafers, that any two of the rollers are apart from each other so much that the orientation flat does not face any two rollers at a time, and that when the orientation flat faces any one of the rollers the rest of the rollers cooperate to hold the wafer so as to prevent the orientation flat from coming in contact with the facing roller.