A Middle-aged Sorcerer's Leisurely Dungeon Conquest - I Got the Strongest Skill by Using a Skill Orb, so I Think I'll Live as I Please~ is a Manga/Manhwa/Manhua in english language, ACTION series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

Haruhiko Ito, a company employee, is fed up with his busy work life and decides to quit and become a "seeker" who makes a living by exploring dungeons. In the beginning, he uses several skill orbs to acquire special abilities, but he keeps getting nothing. The last orb was also a failure... but what he got was the most powerful skill, "sorcery," which allows him to acquire a huge amount of magical knowledge! An ex-employee seeker becomes a savior with the strongest skill! The first volume of the long-awaited comic book adaptation of the adventure fantasy that ranked No.1 in "Syosetsu" genre rankings for daily, weekly, and monthly!