SEPARATOR FOR LEAD ACID BATTERY

[Problem] A separator for a valve-regulated lead acid battery that has suppressed losing the thickness (reduction of compressive force) of the separator and prolonged a cycle lifetime is provided. [Solution] The separator for a valve-regulated lead acid battery includes a sheet formed through wet papermaking mainly containing glass fibers, and has an MD/CD strength ratio shown by the following expression (1) of 1.5 or less and 60 kPa compressive force in liquid immersion shown by the following expression (2) of 65% or more: MD/CD strength ratio=MD strength/CD strength (Expression 1) 60 kPa compressive force in liquid immersion (%) (pressure force after liquid immersion/compressive force in liquid immersion)×100 (Expression 2)