Eesha/eeshaavasyopani

Eesha/eeshaavasyopanishat: This 40th adhyaaya of shukla yajurveda maadhyaandina Samhita

starts with word “eeshaavaashyam.”, hence the name. brahmavidyaa is main important discussion in this. Since it is from mantra bhaaga of veda it is also called mantropanishat.