Not exactly.
The Minoans used two methods of writing, hieroglyphics (probably derived from but not the same as the Egyptian variety) and Linear A, a script but not an alphabet, which may have developed out of the hieroglyphs. Neither has been deciphered.
Linear A developed on the mainland among the barbaric Myceaneans into Linear B script, which has been deciphered and shown to be early Greek.
All attempts to similarly decipher Linear A have failed, which probably means the Minoans spoke a completely unrelated language.
The Minoan language clearly was not Greek, but what it was is still unknown. One theory is that it is Luwian (a language related to Hittite, spoken in Anatolia), but it could be a pre-Indo-European language (Hittite and Luwian belonged to a branch of the Indo-European language family).
The language spoken on mainland Greece in the third millennium B.C., before the arrival of the "Greek speakers," was probably the same or related to Minoan, since similar elements are found in place names on Crete and on the mainland and in non-Greek "loan words" that the Greeks borrowed from the previous inhabitants (such as -ss- or -nth- in words, such as Knossos, Tylissos, Parnassos, kyparissa [cypress], glossa, thalassa, Corinth, terebinthos, erebinthos). There are similar names in Asia Minor such as Halikarnassos and Ephesos.