Disclosed is a thermoplastic resin foamed article, wherein the foamed
article has two opposite surfaces, wherein the foamed article has at
least a skin layer which defines one of the opposite surfaces and has a
porosity of 0% or more but less than 1%, a lower-expansion layer which
has a porosity of not less than 1% but less than 40% and is arranged so
as to be adjacent to the skin layer, and a higher-expansion layer which
has a porosity of not less than 40% but less than 100% and is arranged so
as to be adjacent to the lower-expansion layer, wherein the skin layer,
the lower-expansion layer and the higher-expansion layer are made of the
same thermoplastic resin.