Actually it's comfortable for praying but it has operational hours, 6:00 - 23:00. How could in a public place, a prayer room has operational hours?? It's annoying. My mom and I just arrived at Narita on 22:55, and my mom wanted to do Sholat. But at 23:00 a security came and said the prayer room had to be closed. I ask for additional time because we just arrived. And he just gave us 5 minutes while my mom had not finished her sholat.