To provide an opening/closing member which is high in magnetic attraction property and is reduced in noise in closing, and to provide a partitioning unit.

The opening/closing member is magnetically attracted by providing a pair of bar-shaped members 1a, 1b to be opposite to each other, and soft magnetic members 2a, 2b disposed at the opposite places of the pair of bar-shaped members. An attaching recess 3a is formed in the longitudinal direction of one bar-shaped member 1a, and an attaching recess 3b is formed in the longitudinal direction of another bar-shaped member 1b. The first soft magnet member 2a is attached to the attaching recess 3a so as to allow north pole and south pole to be adjacent in the width direction of the attaching recess 3a. The second soft magnet member 2b is attached to the attaching recess 3b, so as to allow the magnetic poles to be opposite to the magnetic poles of the first soft magnet member 2a.