A closure device of the present invention includes two closure elements, and two sheet materials for integrally disposing the two closure elements. Each of the closure elements includes a base portion, a drawstring portion integrally extending from the base portion, and an adjustment portion including an engaged portion having a shape engageable with the drawstring portion. The base portion of one closure element of the two closure elements and the adjustment portion of the other closure element of the two closure elements are integrally disposed on one of the sheet materials, and the adjustment portion of one closure element and the base portion of the other closure element are disposed integrally on the other of the sheet materials.