not without its worth; not altogether hopeless; not to be undervalued
Used to say that something or someone has more value, ability, or potential than one might assume, often after a disappointing first impression. Commonly follows a noun marked with も.
彼のアイデアも捨てたものではない。
His idea is not without its worth, either.
この古いカメラも捨てたものではない。まだ十分使える。
This old camera isn't altogether hopeless. It's still perfectly usable.
Standard kanji spelling for this set phrase.
Variant using 物 instead of もの; less common but still encountered.
From 捨てる (to throw away) + た (past) + もの (thing) + ではない (is not). Literally 'it is not a discarded thing', implying that something still has value or potential.