Biaxially oriented laminated polyester film having different size particles in a layer thereof

A biaxially oriented laminated polyester film comprising:

• (A) a first thin polyester layer formed from an aromatic polyester containing:
• (a) externally added inert inorganic fine particles having an average particle diameter, d.sub.a, of 0.02 to 0.3 .mu.m, and
• (b) externally added inert organic fine particles whose average particle diameter, d.sub.b, is greater than d.sub.a and is 0.4 to 1.5 .mu.m,
• the above inorganic fine particles (a) being contained in an amount of 0.05 to 1.5% by weight, the organic fine particles (b) being contained in an amount of 0.001 to 1% by weight, the first thin polyester layer having a thickness (t) which satisfies the following expressions (1), (2) and (3) relative to the above d.sub.b,
• d.sub.b .ltoreq.10t-1 (1)
• d.sub.b .ltoreq.0.5t-1 (2)
• 0.12.ltoreq.t.ltoreq.3.0 (3)
• wherein t is a thickness of the layer, and the unit for t and d.sub.b is .mu.m, and
• (B) a second polyester layer formed from an aromatic polyester, said first thin polyester layer being present on a surface of said second polyester layer.