Prosecutors at the court in Versailles, outside Paris, say IKEA France collected details on hundreds of existing and prospective staff, including confidential information about criminal records, as part of a "spying system", sometimes targeting union members and their representatives.
They have called for "exemplary penalties," including fines and a prison term, in order to protect the private lives of all employees.
In evidence earlier in the trial former director of risk management for the French company, Jean-François Paris, accused ex-chief executive Jean-Louis Baillot of ordering the scheme in 2007.
"I practically never saw Mr Paris," said Baillot, insisting his former colleague had "complete autonomy" and did not answer to him.
600,000 euros each year for private detectives
Jean-François Paris has admitted that he regularly sent lists of names of people "to be tested" to private investigators, whose combined annual bill could run up to 600,000 euros, according to court documents.
Mr Paris says the retailing giant and its former executives have sought to shift the blame solely onto his shoulders, after devising the scheme in response to a series of armed robberies.
"It's cowardly of the company . . . they put the system into place and then left me to fend for myself," he told the court.
IKEA France employs 10,000 people. The company insists that it is opposed to the idea of secretely invgestigating anyone.
In calling for a three-year prison term for Jean-Louis Baillot, the prosecution said he had interfered in the lives of more than 400 employees and should have his own life marked by a period behind bars. If found guilty, Baillot would benefit from an automatic two-year suspension.
A verdict is to be delivered on Thursday.
