It is hard to determine from just a photo, but it looks a lot like a circa mid 1980's business dress. It probably came with a belt. Looks like the skirt is a rayon or poly-rayon woven in a linen-look weave and the top is either a polyester or a rayon-acetate (very popular in the 1980s for women's clothing).
Just a guess based on the photos, but I am not seeing a 1960s or 70s influence.