Disclosed herein is a stretched poly(arylene thioether-ketone) film made of a thermoplastic material which comprises (A) 100 parts by weight of a melt-stable poly(arylene thioether-ketone) having predominant recurring units of the formula ##STR1## and having a melting point, Tm of 310.degree.-380.degree. C., a residual melt crystallization enthalpy, .DELTA.Hmc (420.degree. C./10 min) of at least 10 J/g and a melt crystallization temperature, Tmc (420.degree. C./10 min) of at least 210.degree. C., and a reduced viscosity of 0.3-2 dl/g as determined by viscosity measurement at 25.degree. C. and a polymer concentration of 0.5 g/dl in 98 percent by weight sulfuric acid; and optionally, (B) up to 100 parts by weight of at least one of thermoplastic resins and/or up to 15 parts by weight of at least one of fillers. Its production process is also disclosed.