Radheshyam Prasad, who ran a mobile charger factory, was was found hanging from the ceiling fan of his house in Dharamveer Colony of Burari area, by his wife at about 11:30 am, police said.
On being informed, police arrived and rushed him to a hospital where doctors declared him dead. After post mortem, the body was handed over to his family.
The suicide note was found in his pocket, and was addressed to Prime Minister Narendra Modi. Prasad congratulated Modi on becoming the Prime Minister and praised him for ending Congress's "dynasty rule", police said.
"Prasad, who was father of three sons and two daughters, has accused them of being close to their maternal uncles rather than to their paternal relatives. In the note, he accused his wife of diverting all the family money to her own parents and brothers," said a police official.
A case has been registered at Burari police station in this connection and his family is being questioned. Neighbours told police that there were regular tiffs in the family.