Sulfur-containing polymerizable monomer and use thereof

A compound (A) represented by the formula (1):

• wherein
• R1 is a hydrogen atom or an alkali metal atom,
• R2 is a hydrogen atom or an alkali metal atom,
• R3 is a hydrogen atom or a methyl group,
• Z is a divalent or trivalent organic group, and the lines consisting of a solid line and a broken line bonded to Z represent a single bond or a double bond,
• provided that when R1 and R2 are a hydrogen atom, and R3 is a methyl group, Z is not a trivalent organic group including 1,4-phenylene group,
• the compound (A) is not a compound represented by following formula:
• the divalent or trivalent organic group Z in the formula (1) includes one or more groups selected from divalent groups represented by formula (Z1), ether bonds, 1,4-phenylene groups, 1,4-cyclohexylene groups and divalent linear saturated hydrocarbon groups,
• wherein Y1 and Y2 are each independently an oxygen atom, a divalent group represented by —CH2— or a divalent group represented by —NH—, and Y3 is an oxygen atom or a sulfur atom.