An olefin type thermoplastic elastomer which satisfies the following
formulae (I) to (III):
Y.ltoreq.-2X+350 (I)
X<95 (II)
Z.ltoreq.150 (III)
where X, Y and Z are as follows: X: JIS A hardness of a molded product as
measured in accordance with JIS K6253 (no unit); Y: rate of change in the
weight of a molded product measured based on JIS K6258 using IRM903 oil at
120.degree. C. (unit: %); and Z: number of granular structures on an
extruded sheet surface (250 mm.times.1,500 mm) (unit: granular
structures).
