The far-to-mid infrared absorption spectrum of phenanthrene (C14H10) has been measured in an argon matrix at 5 K. Thirty-two fundamental bands have been observed; one is detected for the first time (m54) and eight are observed for the first time at temperatures below room temperature (m43, m42, m66, m65, m21, m63, m18 and m55). The relative intensities of these 32 bands have been obtained; seven (m42, m66, m65, m21, m18, m55, m54) are measured for the first time and two (m43, m63) are measured for the first time below room temperature.