To provide an efficient method for producing a portable ashtray having a bag body, easy for putting a cigarette butt thereinto, simply closed by folding, and capable of maintaining the folded state.

This ashtray is formed by providing a gap 9 formed in its lengthwise direction at the position with a distance of 1.5-5 fold of the width of a heat seal from the bag end part of a top seal 71 on processing one of the laminated sheet 61 of a four way-sealed bag obtained by heat sealing the four ends of two laminated sheets 61 and 62 obtained by installing at least a soft aluminum foil and a heat sealing layer to a laminated film of a substrate film with sheet of paper.